The increase in human scientific understanding of the various forms of radiant energy and electromagnetic radiation has led to a similar increase in our utilization of same, both as an energy source and otherwise. Concomitant with its growing importance to our society, there has been a continual demand for more and more efficient means by which we might harness and direct radiant energy and electromagnetic radiation for our own purposes.
In the wake of numerous crises over the continued availability of fossil fuels, and in recognition of other pressing environmental concerns, large segments of the population, including campers, cottagers, owners of recreational vehicles, home owners, and people living in third world countries, have increasingly turned to the sun as an inexpensive and viable alternative source of natural energy that is both renewable and readily available. Solar power enthusiasts have started to use concave reflectors as solar heat collectors, and as solar cooking devices. Spherical, parabolic and elliptical concave reflectors have thus far been used to direct substantially parallel waves of radiant and electromagnetic energy to and from their respective focussing areas. Among a large number of other things, concave reflectors and satellite dish antennas have also thus far allowed us to communicate over great distances, to provide patients with effective medical treatment, and even to calculate the distance to neighbouring stars. Now, by using concave reflectors as solar heat collectors, and as solar cooking devices, solar power enthusiasts are able to better direct and concentrate the radiating electromagnetic waves of the sun, so as to provide concentrated heat, among other things, in order to cook food, and to heat and sterilize water for drinking and washing purposes.
There have, however, been a number of problems associated with the practical use of concave reflectors in the context of solar cooking. First of all, because solar cooking is an activity that is most efficiently performed outside in the direct and unfiltered light of the sun, concave reflectors used for this purpose must be weather-resistant and/or easily movable to a sheltered location in the event of inclement and potentially damaging weather conditions. As such, there is a significant need for a cooking device that may be easily transported. This need is made even more predominant and pressing in the case of campers, who also require that such concave reflectors be capable of being compactly carried in transit, such as, for example, inside of a back-pack.
Several methods and devices have been developed to address these needs, such as, for example, by producing foldable and/or collapsible concave reflectors. Concave reflectors of this sort are typically formed from a plurality of blade members attached together at a respective one of their ends, about a common axis, so as to be rotatable thereabout, and slidably foldable or collapsible in fan-like manner. An example of such a device is seen in U.S. Design Pat. No. D245,884 (Jackson) for a Foldable Solar Cooker. According to designs of this general sort, however, the reflective surface of the concave reflector may have a tendency to become scratched, since the reflective surface of each of its respective blade members slides in frictional and direct juxtaposed relation to the rear surface of an adjacent blade member. Over time, and with the repeated folding or collapsing of concave reflectors of this general design, the reflective surface thereof may have a tendency to become scratched, and surface irregularities may be created thereon, in the manner as aforesaid. Naturally, these scratches and surface irregularities, with their tendency to diffuse and reflect incident electromagnetic radiation at odd and unpredictable angles, will affect adversely the ability of such concave reflectors to effectively direct radiant energy to and from the desired focal area, and likewise, they may have a negative effect on the proper and efficient functioning of such reflectors, whether as solar cookers or otherwise.
An example of a device that has been developed to overcome these problems is seen in U.S. Pat. No. 4,112,917 (Lang) for a Solar-ray Heating Apparatus. The Lang patent discloses a solar cooker design that has twelve blade members, each individually and removably secured between two central disc members. Each blade member has, at a respective narrow inner end portion thereof, a bent tab which engages a corresponding slot to hold the blade member on one of the discs and in an angular position relative to the other blade members. Each one of the blade members is detachable both from each other one of the blade members, and from the two central disc members. As well, according to the Lang design, two of the twelve blade members have a different shape from that of the others, so as to create a radial gap in the reflective surface of the reflector assembly, and so as to accommodate a post for attachment of the concave reflector to a tripod in an in-use configuration. A problem associated with concave reflector assemblies of this general design, however, stems from the fact that their reflective surface is interrupted or non-continuous (i.e., it does not extend in a full three hundred and sixty degrees about the disc members), such that there they have consequently lower cooking efficiency. A main problem is that the differing shapes of the various blade members necessitate an increased cost in the manufacture and repair of reflector assemblies according to this general design. What is needed, therefore, is an alternate design for a concave reflector assembly that utilizes a uniform size and shape for all of its individual blade members so that all of its blade members might be formed from a single mould, thereby reducing manufacturing and replacement costs.
It should also be noted that, although the Lang design specifies the use of bent tabs engaging corresponding slots so as to hold the blade members in place relative to the discs, this connection means is insufficient on its own, as disclosed by Lang, to ensure that the blade members and discs are held in locked and secured relation with respect to one another. Instead, concave reflectors according to the Lang design have an added level of complexity, insofar as they also rely on a centrally located secondary connection means that involves the sandwiching of their blade members between their two disc members, as aforesaid. Without the secondary connection means, the blade members of concave reflectors according to the Lang design could easily and unpredictably become detached from the disc members, both in strong weather conditions and when moving the reflector. Moreover, the Lang blade members may have a tendency to easily and unpredictably move out of planar alignment with one another along their radial edges, thereby disrupting the integrity of the concave surface of the reflector.
Other concave reflector assemblies having detachable blade members, and utilizing tab and slot connection means, have likewise been unreliable in ensuring that the blade members are held in locked and secured relation with respect to each other. In order to be properly usable in a wide array of geographic conditions and locations, an easily transportable solar cooking reflector assembly is required that is formed from a plurality of blade members, that utilizes a tab and slot connection means, and that also has a simple locking means for easily and selectively securing an individual tab member with respect to a corresponding slot, so as to allow easy disengagement of said tab from said slot and simple disassembly of the concave reflector as a whole. To date, concave reflector assemblies utilizing separable blade members with tab and slot connection means have either been unreliable and prone to detachment of their respective blade members, or have been notoriously hard to disassemble and difficult to effect disengagement of one blade member from another. In the former situation, the blade members have been known to become detached from each other at often particularly inopportune times, such as whilst a user is hosting a family cook-out. Conversely, in the latter event, disassembly of the prior art reflector assemblies has often been frustrated or become impossible when necessary to move the reflector on short notice, such as, for example, following the sudden onset of a thunderstorm. In either case, solar cooking enthusiasts have, to date, only been able to acquire solar reflectors that are inadequate to ensure such undesirable situations are consistently avoided.
The primary object of the invention is to provide a portable concave reflector assembly that is simple and inexpensive to manufacture and which is readily repairable by modular replacement of parts.
Another object of one aspect of the invention is to provide a portable concave reflector assembly that is capable of reflecting radiant and electromagnetic energy to a desired general focal area.
A further object of one aspect of the invention is to provide a portable concave reflector assembly that has a substantially continuous reflective surface.
Another object of the invention is to provide a portable concave reflector assembly that may be easily disassembled and transported.
A still further object of the invention is to provide a portable concave reflector assembly that has a reduced tendency to become scratched during transport and when in a disassembled configuration.
Yet another object of one aspect of the invention is to provide a portable concave reflector assembly that may be easily disassembled into completely separate and stackable portions for easy transport.
Yet still another object of one aspect of the invention is to provide a portable concave reflector assembly that, in the disassembled configuration, is of a suitable size and weight to be easily carried by a user inside of a back-pack or similar-sized carrying case.
Still another object of one aspect of the invention is to provide a portable concave reflector assembly that is constructed from a hub member together with a plurality of identical blade members that are easily replaceable.
A further object of the invention is to provide a portable concave reflector assembly in which each blade member is in selectively locked and secured relation with respect to each adjacent blade member and with respect to the hub member.
A still further object of the invention is to provide a portable concave reflector assembly that has detachable blade members, and that utilizes tab and slot connection means for selectively locking and securing each blade member with respect to each adjacent blade member and with respect to the hub member.
Yet still another object of the invention is to provide a portable concave reflector assembly that is constructed from light-weight flexible materials.
A still further object of one aspect of the invention is to provide a portable concave reflector assembly that may be easily mounted on a support, such as a standard camera tripod.
Another object of one aspect of the invention is to provide a portable concave reflector assembly of suitable size and focussing qualities so as to be useful as a solar cooker.
A further object of one aspect of the invention is to provide a portable concave reflector assembly that is capable of reflecting substantially parallel waves of radiant and electromagnetic energy from a focal area.
Yet another object of one aspect of the invention is to provide a portable concave reflector assembly that may be easily directed towards an incoming source of visible light.
A yet further object of the invention is to provide a portable concave reflector assembly that is of simple, secure, and reliable construction.
A still further object of the invention is to provide a portable concave reflector assembly that is inexpensive and easy to manufacture, transport, install, disassemble, and repair.